Ring gears have been formed using different methods in manufacturing processes. One such process is to utilize a length of bar stock which is rolled or otherwise formed into a coil, after which, the coils are cut by a saw to provide a plurality of open ended rings. The open ends of the ring are welded together and the weld excess is trimmed from the blank. The blank is then coined and sized and the teeth are hobbed into the periphery of the ring blank.
Another method of manufacturing a gear is described in U.S. Pat. No. 1,632,818 issued Jun. 21, 1927, to Black. The method utilized by Black is to cut a toroidal blank from a tube stock after which a ring gear or blank is forced to the size of the final ring gear member, and the teeth are cut into the ring gear blank.